Evidence law controls what information will be admissible in court and when, how, and by whom it may be presented. It shapes not only the trial decisions of lawyers, judges, and juries, but also many other pretrial and trial decisions and behaviors – for example, by police (whether to initiate a search) and defendants (whether to take a plea deal). Even when the relevant evidence law is known, these decisions are made under great uncertainty. Parties often do not know whether key evidence will be admissible at trial, cannot know how jurors will react to evidence, and, particularly in the criminal context, may not know what evidence their adversary possesses. With all these applications and uncertainties, understanding how legal decisions are made depends on understanding both evidence law itself and the human reasoning processes that created and use it. This chapter thus describes the interplay of evidence law and decision-making across a variety of legal settings and, accordingly, makes frequent references to other chapters in this book.

The focus of this book is the uniform Evidence Act (referred to throughout as ‘the Act’ or ‘the Acts’). The Act has not been introduced in Queensland, South Australia or Western Australia, where each state’s Evidence Act and the common law apply. However, the Act is still an important reference guide for those states due to the connection between the common law and the Act. Despite the differences between jurisdictions that have adopted the Act, there is a significant degree of uniformity. Accordingly, in this book the provisions that are extracted to indicate the rules in relation to the Act come from the Commonwealth Act. Any important jurisdictional differences are separately identified.

This chapter considers the legislative history and sets out some fundamental introductory concepts that are used frequently in evidence law and the trial process. This chapter is merely an introductory overview; specific topics are dealt with in substance in subsequent chapters.

This chapter focuses on the exclusionary powers of the trial judge. Two forms of exclusion are examined: discretionary, where the trial judge has a choice whether to exclude the evidence; and mandatory, where the trial judge is required to do so. The discretions under the Act play a more significant role than the discretions at common law in determining the admissibility of evidence, as noted in the extract below. This may be because the Act adopts the logical relevance test. However, despite evidence being admissible and relevant, the trial judge has the discretion to exclude the evidence. Further, many exclusionary rules of evidence at common law (discussed in the earlier chapters) are relaxed and the Act adopts a more flexible approach to the admissibility of evidence.

This chapter first considers the discretionary and mandatory exclusions regulated by Part 3.11 (ss 135–9) of the Act. The concepts of ‘probative value’ and ‘unfair prejudice’ govern the exercise of the discretions. The chapter then considers how unreliability may affect the weight of the evidence: Parts 4.4 and 4.5 (ss 164–165B) have altered the common law.

This chapter explains the rule against hearsay and its exceptions. First, it sets out what hearsay is and some of the common law cases that contributed to its development. It then explains how hearsay is defined under the Act. The chapter then proceeds to explain the various uses for which evidence may be adduced and the different exceptions available under the Act. It is important to note that facts in issue and facts relevant to facts in issue are critical to understanding the purposes behind tendering hearsay evidence.

Hearsay evidence relies not on direct witness testimony but on another witness’s statement about a ‘previous representation’. The rationale for developing the rule against hearsay at common law was that these out-of-court previous representations were usually made by a person whose evidence was not available to be tested. The main concern at common law was whether such evidence was reliable. The witness giving the hearsay evidence could be cross-examined as to what they perceived, but the credibility of the maker of the statement could not be tested.

This chapter examines tendency and coincidence as two categories of evidence and the rules for their admissibility that apply in civil and criminal proceedings. The tendency rule in s 97 excludes tendency (propensity evidence), which is evidence of conduct, character or reputation that is adduced to show or prove a tendency to act in a particular way or to have a particular state of mind, unless certain conditions are met. The coincidence rule in s 98 excludes evidence of two or more events (similar fact evidence) that is adduced to prove that a person did a particular act or had a particular state of mind on the basis that ‘it is improbable that the events occurred coincidentally’, unless certain conditions are met.

The chapter then examines two thresholds for admission of these. First, the evidence must have ‘significant probative value’. Second, where the prosecution is adducing the evidence in criminal proceedings, it must satisfy the additional hurdle of s 101(2). Finally, the chapter will consider the circumstances where such evidence is admitted for a purpose other than proving tendency or coincidence.

This chapter explains the sections of the Act and the common law principles governing the admission of opinion evidence. Critical to understanding the opinion rule is understanding what an ‘opinion’ is: this triggers the application of the rules on the exclusion or admission of such evidence.

The regulation of opinion evidence under Part 3.3 (ss 76–80) is relatively simple. Nonetheless, these rules have raised subtle problems in practice. Because of its inferential nature, opinion evidence is, in principle, excluded by s 76. However, exceptions are set out in ss 77–9.

This chapter thus explains opinion evidence, the exclusion of opinion evidence, the exceptional admission of opinion evidence and the scope of application of the opinion rule. In order to be admissible, an opinion must rationally affect, either directly or indirectly, the probability of a fact in issue in the proceedings, thus satisfying the requirements of s 55.

The final chapter of this text provides extended questions designed to test students' understanding and knowledge of evidence law as a whole. Each question combines multiple elements of the Uniform Evidence Act to ensure students understand how sections work together.

This chapter considers the rules affecting confessions and admissions in civil and criminal proceedings. Parties can make admissions because a previous representation can constitute an admission before there is even any case. As a matter of terminology, in criminal proceedings, however, admissions involve the defendant acknowledging only a limited aspect of the case against them, whereas a confession involves a full acknowledgement of guilt. Despite these technical differences, the term ‘admissions’ is used in the Act, and therefore in this chapter for consistency.

The first issue this chapter addresses is whether the evidence adduced is in fact an admission. This is followed by an explanation of the statutory rules and cases pertaining to mandatory electronic recording of admissions. The chapter considers the voluntariness and reliability requirements under ss 84 and 85. The types of statements and conduct that may amount to evidence of an admission in civil and criminal proceedings are explored. Finally, the unfairness discretion under the common law and the role of s 90 are considered.

This chapter discusses the rights (‘privileges and immunities’) that allow a party to resist compulsory demands for information. Privileges have a long history in the common law, with some departure from traditional privilege rules arising in statutory formulations. Privilege is a ‘bar to compulsory process for the obtaining of evidence rather than a rule of inadmissibility’. However, a successful claim of privilege will result in the exclusion of evidence, derogating from the general principle that all relevant evidence should be admitted.

Privilege can generally be regarded as an evidentiary right, allowing individuals to refuse to disclose evidence. In some cases, privileges allow directions to be given to others not to disclose. Some privileges extend to corporate entities. Privileges may arise because of the circumstances in which information is communicated, or the way in which it may be used.

The common law’s stance on privilege and the consequent restriction on access to evidence are reflected to a large extent in the Acts. Nonetheless, the categories of privilege have expanded under the legislation and, inevitably, anomalies have arisen between the two branches.

This chapter discusses the provisions of the Act that address character evidence. The term ‘character evidence’ is not defined in the legislation, so that some recourse to the common law is required. However, Part 3.8 of the Act provides a simple mechanism allowing evidence of character to be adduced in criminal proceedings, as follows:

• Exclusionary rules that would prevent a defendant from adducing evidence of good character (the hearsay, opinion, tendency and credibility rules) do not apply; and

• If the defendant adduces evidence of good character (whether by giving evidence or through the testimony of another witness) then the prosecution, or another defendant, can respond with evidence of bad character (because the same exclusionary rules also do not apply).

This chapter is about the admissibility of evidence in court as opposed to the adducing of evidence in court. The concept of relevance has a non-legal meaning where it assists in determining an issue or question in a rational manner. Likewise, the fundamental rule in evidence law is that evidence that is relevant is admissible, unless it is excluded by one of the rules of exclusion. Where the evidence is irrelevant, it is inadmissible, and there are no rules of inclusion. Therefore, relevance is the first hurdle in considering whether an item of evidence is to be admitted in court. Relevance is a significant concept that is, and should be, considered when reading about the other topics discussed in this book.

To be admissible, evidence must be relevant to a fact in issue. In other words, the item of evidence must be able to affect the assessment of the probability that the fact in issue exists. Facts in issue are determined by reference to the substantive law. If an item of evidence assists the tribunal of fact to decide the issue rationally, it will be relevant.

This chapter deals with a range of matters relating to the facilitation of proof (mostly found in ch 4 of the Act) and ancillary matters (found in ch 5 of the Act). Although these provisions are somewhat technical, many are important in practice, as they allow decisions to be reached without evidence having to be taken on some issues. They also regulate the ways in which certain kinds of information, such as that contained in public documents and registers, may be used. Other aspects of proof, such as the standards of proof applying in civil and criminal proceedings, as well as judicial notice, are dealt with in Chapter 1 of this book. Warnings, although falling within ch 4 of the Act, are discussed together with discretions and limiting directions in Chapter 12 of this book.

This chapter explains the sections of the Act and the principles of common law concerning competence and compellability of witnesses and how evidence can be adduced from witnesses. Adducing evidence, in contrast to admitting evidence, refers to the witness giving evidence in court. Generally, our adversarial system favours witnesses giving oral evidence as opposed to any other form. This chapter also discusses certain categories of witnesses who are called to give evidence (complainants in sexual assault and rape cases, children, and people who are cognitively impaired) and the special arrangements that have been introduced to alleviate any disadvantage when such witnesses give evidence. The chapter then focuses on one of the most important aspects of our adversarial system – the proving of facts by having witnesses give oral evidence. In court, witnesses are often examined in three stages: examination-in-chief, cross-examination and re-examination. The chapter explains the rules pertaining to refreshing memory in and out of court and the rule in Browne v Dunn. Finally, it briefly considers adducing documents and other types of evidence.

This chapter explains credibility evidence under Part 3.7 of the Act and the common law principles governing the admission of credibility evidence. Central to this topic is what constitutes credibility evidence. This determines the application of the rules on exclusion or admission of such evidence.

In general, credibility evidence is evidence that is directly relevant to the establishment of the credibility of a witness or another person for the ultimate purpose of establishing the facts in issue. As a consequence, credibility evidence is ‘collateral’ with respect to the establishment of the primary facts in issue in a proceeding. From the perspective of relevance, credibility evidence is admissible, even though it is collateral. From the perspective of admissibility, credibility evidence is initially excluded (‘primarily’) because it is collateral, but is then admitted (‘secondarily’) under specific exceptions.

The chapter thus discusses credibility evidence; exclusion of credibility evidence about a witness under the credibility rule; exceptions that permit admission of credibility evidence about a witness; and the admission of credibility evidence about persons other than witnesses.

This chapter explains the sections of the Act and the principles of common law concerning identification evidence. The Act addresses identification evidence in Part 3.9 (ss 113–16), which only applies in criminal proceedings. Identification evidence is evidence used to prove the identity of a defendant in a criminal proceeding, as part of the case against that person. For example, there may be no dispute that a crime occurred, but the defence position at trial is that the defendant was not the offender. The prosecution will have to prove with identification evidence that the defendant was the same person as the offender.

There are three main forms of identification evidence: visual, picture and voice identification. Visual and picture identification are dealt with in detail in the Act, but voice identification is not, despite falling within the scope of ‘identification evidence’ as defined in the Act’s Dictionary. Also not dealt with as identification evidence in the Act is evidence used to establish the identity of someone other than a criminal defendant (e.g. a victim), any party in a civil proceeding or an object.